he U.S. embassy in Havana. Senior U.S. officials say the United States is withdrawing about 60 percent of its staff out of Cuba and warning American travelers not to visit due to attacks on U.S. dipomats onthe island. Cuba has denied responsibility. Desmond Boylan AP

Cuban Americans seeking to have their relatives join them from the island will not be able to do so — at least for the time being — as a result of a significant withdrawal of staff from the U.S. Embassy in Havana announced on Friday.

It is not known how long the suspension of the visa reunification program will last.

The suspension is the result of the withdrawal of more than half of the American staff from its the embassy in Havana following mysterious sonic attacks that have caused several health problems to about 20 diplomats, officials in Washington announced Friday.

Additionally, Washington will issue a new alert warning Americans not to travel to the island due to the attacks.